Summer-type hypersensitivity pneumonitis

Diagnosis and management of hypersensitivity pneumonitis in adults: A position statement from the Thoracic Society of Australia and New Zealand

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) relating to specific occupational, environmental or medication exposures. Disease behaviour is influenced by the nature of exposure and the host response, with varying degrees of lung inflammation and fibrosis seen within individuals. The differentiation of HP from other ILDs is important due to distinct causes, pathophysiology, prognosis and management implications. This Thoracic Society of Australia and New Zealand (TSANZ) position statement aims to provide an up-to-date summary of the evidence for clinicians relating to the diagnosis and management of HP in adults, in the Australian and New Zealand context. This document highlights recent relevant findings and gaps in the literature for which further research is required.

Effect of warm and humid days on the positivity rate of anti-Trichosporon asahii antibody test for the diagnosis of summer-type hypersensitivity pneumonitis

BACKGROUND

Summer-type hypersensitivity pneumonitis (SHP) has been reported to occur during warm and humid summer seasons in Japan; however, the effect of weather conditions on SHP remains unknown. Anti-Trichosporon asahii antibody (TaAb) test is highly specific and useful for the diagnosing SHP. Therefore, we aimed to investigate the impact of weather conditions on SHP by examining the relationship between the positivity rate of TaAb and warm and humid days.

METHODS

TaAb test data from June 2013 to June 2020 were obtained from major commercial laboratories to determine the number of samples and positivity rate of TaAb by prefecture. Using the Japan Meteorological Agency database, we counted the warm and humid days (maximum temperature ≥25 °C and average humidity ≥80 %) for each prefecture. Negative binomial regression was employed to examine the relationship between the positivity rate of TaAb and the number of warm and humid days per month.

RESULTS

A total of 79,211 samples and 7626 positive samples (9.6 %) were identified. We found that the number of warm and humid days, 1 or 2 months prior to testing for TaAb, was associated with the positivity rate of the test. An increase in the positivity rate by 1.6 % and 2.9 % was observed with every 1-day increase in warm and humid days 1 month and 2 months before the test, respectively.

CONCLUSIONS

Our TaAb analysis revealed a significant increase in TaAb positivity 1 or 2 months after periods of warm and humid days.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Hypersensitivity pneumonitis: An infrequent cause of chronic lung fibrosis in Africa?

-

Waterproofing spray-associated pneumonitis review: Comparison with acute eosinophilic pneumonia and hypersensitivity pneumonitis

Waterproofing spray-associated pneumonitis (WAP) proceeds to acute respiratory failure and is characterized by diffuse bilateral ground-glass opacities on computed tomography; however, the detailed characteristics of WAP are unknown. Therefore, this study identified the characteristics of WAP from comparisons with those of acute eosinophilic pneumonia (AEP) and hypersensitivity pneumonitis (HP), which show similar features to WAP.Adult patients with WAP, AEP, and HP treated in Fukujuji Hospital from 1990 to 2018 were retrospectively enrolled. Furthermore, data from patients with WAP were collected from publications in PubMed and the Japan Medical Abstracts Society and combined with data from our patients.Thirty-three patients with WAP, eleven patients with AEP, and thirty patients with HP were reviewed. Regarding age, sex, smoking habit, and laboratory findings (white blood cell count, C-reactive protein level, and serum Krebs von den Lungen-6 level), WAP and AEP were not significantly different, while WAP and HP were significantly different. The duration from symptom appearance to hospital visit was shorter in patients with WAP (median 1 day) than in patients with AEP (median 3 days, P = .006) or HP (median 30 days, P < .001). The dominant cells in the bronchoalveolar lavage fluid of patients with WAP, AEP, and HP were different (macrophages, eosinophils, and lymphocytes, respectively).The characteristic features of WAP were rapid disease progression and macrophage dominance in the bronchoalveolar lavage fluid, and these characteristics can be used to distinguish among WAP, AEP, and HP.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Yeasts

Yeasts are unicellular organisms that reproduce mostly by budding and less often by fission. Most medically important yeasts originate from Ascomycota or Basidiomycota. Here, we review taxonomy, epidemiology, disease spectrum, antifungal drug susceptibility patterns of medically important yeast, laboratory diagnosis, and diagnostic strategies.

A case of familial hot tub lung

Hot tub lung is a lung disease caused by Mycobacterium avium complex. We report the first case of familial hot tub lung appearing simultaneously in a husband and wife. Our case supports the consideration that hot tub lung is a hypersensitivity pneumonitis rather than an infectious lung disease. It also suggests that the state of hot tub lung changes seasonally depending on temperature variations, in a manner similar to summer-type hypersensitivity pneumonitis. This case demonstrates similarities between hot tub lung and summer-type hypersensitivity pneumonitis in regards to familial occurrence and seasonal changes in the disease state.

Familial Summer-type Hypersensitivity Pneumonitis: A Review of 25 Families and 50 Cases in Japan

Summer-type hypersensitivity pneumonitis (SHP) is the most common form of pneumonitis in Japan; it accounts for 74% of all cases. It has been reported that 19.5-23.8% of SHP cases occur in families who live in the same house. We present our SHP cases and review 50 familial cases in 23 families that were reported in Japan (including our own) and 48 cases that were previously described in 22 articles published between January 1982 and October 2011. To the best of the authors' knowledge, this is the first review article in English to document the familial occurrence of SHP in Japan.

A unique case of hot tub lung worsening during the winter

Summer-type hypersensitivity pneumonitis includes a spectrum of granulomatous lung diseases that result from the inhalation of Trichosporon species in the summer. Hot tub lung is a granulomatous lung disease caused by the inhalation of water aerosols containing non-tuberculous mycobacteria. We herein describe a case of hot tub lung that deteriorated during the winter season. Every winter, the patient's symptoms, laboratory findings and chest images worsened. Genetically identical Mycobacterium avium strains were detected in his sputum and bathtub. The circulation of bathtub water during the winter months only exacerbated his symptoms in the winter.

Multiple species of Trichosporon produce biofilms highly resistant to triazoles and amphotericin B

Invasive infections caused by Trichosporon spp. have increased considerably in recent years, especially in neutropenic and critically ill patients using catheters and antibiotics. The genus presents limited sensitivity to different antifungal agents, but triazoles are the first choice for treatment. Here, we investigated the biofilm production and antifungal susceptibility to triazoles and amphotericin B of 54 Trichosporon spp. isolates obtained from blood samples (19), urine (20) and superficial mycosis (15). All isolates and 7 reference strains were identified by sequence analysis and phylogenetic inferences of the IGS1 region of the rDNA. Biofilms were grown on 96-well plates and quantitation was performed using crystal violet staining, complemented with Scanning Electron Microscopy (SEM). Susceptibility tests for fluconazole, itraconazole, voriconazole and amphotericin B were processed using the microdilution broth method (CLSI) for planktonic cells and XTT reduction assay for biofilm-forming cells. Our results showed that T. asahii was the most frequent species identified (66.7%), followed by T. faecale (11.1%), T. asteroides (9.3%), T. inkin (7.4%), T. dermatis (3.7%) and one T. coremiiforme (1.8%). We identified 4 genotypes within T. asahii isolates (G1, G3, G4 and G5) and 2 genotypes within T. faecale (G1 and G3). All species exhibited high adhesion and biofilm formation capabilities, mainly T. inkin, T. asteroides and T. faecale. Microscopy images of high biofilm-producing isolates showed that T. asahii presented mainly hyphae and arthroconidia, whereas T. asteroides exhibited mainly short arthroconidia and few filaments. Voriconazole exhibited the best in vitro activity against all species tested. Biofilm-forming cells of isolates and reference strains were highly resistant to all antifungals tested. We concluded that levels of biofilm formation by Trichosporon spp. were similar or even greater than those described for the Candida genus. Biofilm-forming cells were at least 1,000 times more resistant to antifungals than planktonic cells, especially to voriconazole.

Familial summer-type hypersensitivity pneumonitis in Japan: two case reports and review of the literature

BACKGROUND

Hypersensitivity pneumonitis is defined as an allergic lung disease that occurs in response to inhalation of fungal antigens, bacterial antigens, chemicals, dusts, or animal proteins. The incidence of summer-type hypersensitivity pneumonitis is higher in the summer season, especially in Japan, due to the influence of the hot and humid environment and the common style of wood house or old concrete condominiums.

CASE PRESENTATION

The present report describes a case of a middle-aged married couple who lived in the same house and who simultaneously suffered from summer-type hypersensitivity pneumonitis. This report analyzes these two cases in terms of environmental research and its microbiological, radiological, and pathological aspects. This case report is followed by a review of family occurrences of summer-type hypersensitivity pneumonitis from 22 studies with a total of 49 patients (including the two present cases) in Japan.

CONCLUSION

Summer-type hypersensitivity pneumonitis may be unrecognized and misdiagnosed as pneumonia or other respiratory diseases. A greater understanding of the clinical, pathologic, and environmental features of summer-type hypersensitivity pneumonitis might help improve diagnosis and delivery of appropriate management for this condition.

The opportunistic yeast pathogen Trichosporon asahii colonizes the skin of healthy individuals: analysis of 380 healthy individuals by age and gender using a nested polymerase chain reaction assay

Deep-seated trichosporonosis is an opportunistic fungal infection with a poor prognosis and high mortality rate. The major causative agent is Trichosporon asahii; its route of infection is not clear. To elucidate whether this microorganism is part of the cutaneous microbiota, we examined skin samples from 380 healthy Japanese ranging in age from 0 to 82 years using a nested PCR assay. The colonization frequency of T. asahii increased with age up to 13-15 years in male and 30-39 years in female subjects, subsequently decreasing gradually in both sexes until senescence. Of the nine genotypes of the intergenic spacer region of the T. asahii rRNA gene, type 1 predominated (81.7%), followed by types 4 (6.7%) and 6 (5.5%). The distribution of identified genotypes was similar to that for T. asahii isolated from clinical specimens (blood and urine) of patients with deep-seated trichosporonosis and quite different from that of environmental isolates. Additionally, T. asahii DNA was detected stably from skin samples over 1 year. The opportunistic yeast pathogen T. asahii is part of the cutaneous fungal microbiota in humans. Cutaneous T. asahii may be one of the routes through which deep-seated trichosporonosis is acquired, whereas environmental T. asahii is not associated with this infection.

Respiratory and allergic health effects of dampness, mold, and dampness-related agents: a review of the epidemiologic evidence

OBJECTIVES

Many studies have shown consistent associations between evident indoor dampness or mold and respiratory or allergic health effects, but causal links remain unclear. Findings on measured microbiologic factors have received little review. We conducted an updated, comprehensive review on these topics.

DATA SOURCES

We reviewed eligible peer-reviewed epidemiologic studies or quantitative meta-analyses, up to late 2009, on dampness, mold, or other microbiologic agents and respiratory or allergic effects.

DATA EXTRACTION

We evaluated evidence for causation or association between qualitative/subjective assessments of dampness or mold (considered together) and specific health outcomes. We separately considered evidence for associations between specific quantitative measurements of microbiologic factors and each health outcome.

DATA SYNTHESIS

Evidence from epidemiologic studies and meta-analyses showed indoor dampness or mold to be associated consistently with increased asthma development and exacerbation, current and ever diagnosis of asthma, dyspnea, wheeze, cough, respiratory infections, bronchitis, allergic rhinitis, eczema, and upper respiratory tract symptoms. Associations were found in allergic and nonallergic individuals. Evidence strongly suggested causation of asthma exacerbation in children. Suggestive evidence was available for only a few specific measured microbiologic factors and was in part equivocal, suggesting both adverse and protective associations with health.

CONCLUSIONS

Evident dampness or mold had consistent positive associations with multiple allergic and respiratory effects. Measured microbiologic agents in dust had limited suggestive associations, including both positive and negative associations for some agents. Thus, prevention and remediation of indoor dampness and mold are likely to reduce health risks, but current evidence does not support measuring specific indoor microbiologic factors to guide health-protective actions.

Genotyping and antifungal drug susceptibility of the pathogenic yeast Trichosporon asahii isolated from Thai patients

Trichosporonosis due to Trichosporon asahii is a life-threatening infection with a very poor prognosis. We analyzed the genotype of intergenic transcribed spacer (IGS) region 1 of the rRNA gene and determined the drug susceptibility of 101 T. asahii isolates obtained from Thai patients to collect basic information on trichosporonosis in Thailand. Of the five genotypes in the IGS region identified in this study, types 1 and 3 were predominant in Thailand. The distribution in Thailand differs from that in other countries, suggesting that there is a geographic substructure among T. asahii clinical isolates. Voriconazole appeared to be the most active drug.

In the Absence of Reactive Oxygen Species, T Cells Default to a Th1 Phenotype and Mediate Protection against PulmonaryCryptococcus neoformansInfection

In recent years, the prevalence of invasive fungal infections has increased, attributed mostly to the rising population of immunocompromised individuals. Cryptococcus neoformans has been one of the most devastating, with an estimated 6-8% of AIDS-infected patients succumbing to Cryptococcus-associated meningitis. Reactive oxygen species (ROS) are potent antimicrobial agents but also play a significant role in regulating immune cell phenotype, but cause immunopathology when produced in excess. We now show that mice lacking phagocyte NADPH oxidase have heightened macrophage and Th1 responses and improved pathogen containment within pulmonary granulomatous lesions. Consequently, dissemination of this fungus to the brain is diminished, an effect that is independent of IL-12. Similar results are described using the metalloporphyrin antioxidant manganese(III) tetrakis(N-ethyl pyridinium-2-yl)porphyrin, which also promoted a protective Th1 response and reduced dissemination to the brain. These findings are in sharp contrast to the protective potential of ROS against other fungal pathogens, and highlight the pivotal role that ROS can fulfill in shaping the profile of the host's immune response.

Chronic hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is traditionally divided on clinical grounds into acute, subacute, and chronic stages. Most biopsy specimens come from patients in the subacute stage, in which there is a relatively mild, usually peribronchiolar, chronic interstitial inflammatory infiltrate, accompanied in most cases by poorly formed interstitial granulomas or isolated giant cells. However, the pathologic features in the chronic, ie, fibrotic stage, are poorly defined in the literature. These features are important to recognize because the chronic stage of HP is often associated with a poor prognosis. We reviewed 13 cases of chronic HP. Where information was available, exposures to the sensitizing agent had generally occurred over a long period of time. Three patterns of fibrosis were seen: 1) predominantly peripheral fibrosis in a patchy pattern with architectural distortion and fibroblast foci resembling, microscopically, usual interstitial pneumonia (UIP); 2) relatively homogeneous linear fibrosis resembling fibrotic nonspecific interstitial pneumonia (NSIP); and 3) irregular predominantly peribronchiolar fibrosis. In some instances, mixtures of the UIP-like and peribronchiolar patterns were found. In all cases, the presence of scattered poorly formed granulomas, or isolated interstitial giant cells, or sometimes only Schaumann bodies indicated the correct diagnosis. In 7 cases, areas of typical subacute HP were present as well. High-resolution CT scans showed variable patterns ranging from severe fibrosis, in some instances with an upper zone predominance, to predominantly ground glass opacities with peripheral reticulation. We conclude that, at the level of morphology, chronic HP may closely mimic UIP or fibrotic NSIP. If no areas of subacute HP are evident, the presence of isolated giant cells, poorly formed granulomas, or Schaumann bodies is crucial to arriving at the correct diagnosis, and the finding of peribronchiolar fibrosis may be helpful. Despite the presence of extensive fibrosis, some patients responded to removal from exposure and steroid therapy.

TGF-beta prevents eosinophilic lung disease but impairs pathogen clearance

Respiratory infections are the third leading cause of death worldwide. Complications arise directly as a consequence of pathogen replication or indirectly due to aberrant or excessive immune responses. In the following report, we evaluate the efficacy, in a murine model, of nasally delivered DNA encoding TGF-beta1 to suppress immunopathology in response to a variety of infectious agents. A single nasal administration suppressed lymphocyte responses to Cryptococcus neoformans, influenza virus and respiratory syncytial virus. The suppression did not depend on the phenotype of the responding T cell, since both Th1 and Th2 responses were affected. During Th2-inducing infection, pulmonary eosinophilic responses were significantly suppressed. In all cases, however, suppressed immunity correlated with increased susceptibility to infection. We conclude that nasal TGF-beta treatment could be used to prevent pulmonary, pathogen-driven eosinophilic disease, although anti-pathogen strategies will need to be administered concordantly.

Analysis of Trichosporon isolates obtained from the houses of patients with summer-type hypersensitivity pneumonitis

Summer-type hypersensitivity pneumonitis (SHP) is type III or IV allergies developed by repeated inhalation of arthroconidia of Trichosporon species. We identified 105 strains obtained from the homes of 36 SHP patients by analysis of the intergenic spacer (IGS) 1 region, which is located between the 26S and 5S rRNA genes; in addition, we analyzed the IGS genotypes of the strains. Serologically, Trichosporon species are classified as serotype I, II, III, or I-III. Of the 105 strains, 43 (41.1%), 53 (50.5%), and 9 (8.6%) strains were isolated as serotypes I, II, and III, respectively. Serotype I, II, and III strains were recovered from 19 (52.8%), 29 (80.6%), and 4 (11.1%) of the 36 houses of SHP patients, respectively. No serotype I-III strains were isolated from the houses. Of 43 serotype I strains, 42 (97.7%) were identified as Trichosporon dermatis, and the remaining one was T. terricola. Of 53 serotype II strains, 37 (69.8%) were identified as T. asahii, and the remaining serotype II isolates were T. aquatile (1.9%), T. coremiiforme (7.5%), T. faecale (1.9%), T. japonicum (15.1%), and T. ovoides (3.8%). There were nine serotype III strains comprised of T. montevideense (77.8%) and T. domesticum (22.2%). Intraspecies diversity was found only in T. asahii. This microorganism also causes opportunistic infections (trichosporonosis); seven genotypes of its IGS 1 region have been identified. While the strains of T. asahii obtained from Japanese patients with trichosporonosis were genotype I, the strains from the houses of SHP patients were genotype III. Based on our analysis, we conclude that the strains that play the most significant roles in the development of SHP are T. dermatis, T. asahii genotype 3, and T. montevideense, representing serotypes I, II, and III, respectively.

Trichosporon mycotoxinivorans sp. nov., A New Yeast Species Useful in Biological Detoxification of Various Mycotoxins

A yeast strain isolated from the hindgut of the lower termite Mastotermes darwiniensis (Mastotermitidae) was found to represent a new member of the genus Trichosporon. Trichosporon mycotoxinivorans is closely related to T. loubieri on the basis of the phylogenetic trees based on the D1/D2 region of 26S rDNA, an approx. 600 bp fragment of the 18S rDNA and both ITS regions. However, the two species differ at nine positions in the D1/D2 region of 26S rDNA. The IGS1 region of T. mycotoxinivorans is 401 bp long. T. mycotoxinivorans is distinguished from T. loubieri by its ability to assimilate inulin and galactitol, and its inability to grow at 40 degrees C. The name of this newly isolated strain refers to an important characteristics of T. mycotoxinivorans to detoxify mycotoxins such as ochratoxin A and zearalenone. Therefore this strain can be used for the deactivation of the respective mycotoxins in animal feeds.

OX40 ligation on activated T cells enhances the control of Cryptococcus neoformans and reduces pulmonary eosinophilia

Pulmonary eosinophilia induced in C57BL/6 mice after Cryptococcus neoformans infection is driven by CD4(+) Th2 cells. The immunological mechanisms that protect against eosinophilia are not fully understood. Interaction of OX40 (CD134) and its ligand, OX40L, has been implicated in T cell activation and cell migration. Unlike CD28, OX40 is only expressed on T cells 1-2 days after Ag activation. Manipulation of this pathway would therefore target recently activated T cells, leaving the naive repertoire unaffected. In this study, we show that engagement of OX40 by an OX40L:Ig fusion protein drives IFN-gamma production by CD4(+) T cells and reduces eosinophilia and C. neoformans burden in the lung. Using gene-depleted mice, we show that reduction of eosinophilia and pathogen burden requires IL-12 and/or IFN-gamma. C. neoformans infection itself only partially induces OX40L expression by APCs. Provision of exogenous OX40L reveals a critical role of this pathway in the prevention of C. neoformans-induced eosinophilia.

Prior exposure to live Mycobacterium bovis BCG decreases Cryptococcus neoformans-induced lung eosinophilia in a gamma interferon-dependent manner

Some common childhood infections appear to prevent the development of atopy and asthma. In some Mycobacterium bovis BCG-vaccinated populations, strong delayed-type hypersensitivity responses to mycobacterial antigens are associated with a reduced risk of atopy. Although BCG exposure decreases allergen-induced lung eosinophilia in animal models, little attention has been given to the effect of immunity to BCG on responses against live pathogens. We used the murine Cryptococcus neoformans infection model to investigate whether prior BCG infection can alter such responses. The present study shows that persistent pulmonary BCG infection of C57BL/6 mice induced an increase in gamma interferon, a reduction in interleukin-5, and a decrease in lung eosinophilia during subsequent Cryptococcus infection. This effect was long lasting, depended on the presence of live bacteria, and required persistence of mycobacterial infection in the lung. Reduction of eosinophilia was less prominent after infection with a mutant BCG strain (DeltahspR), which was rapidly cleared from the lungs. These observations have important implications for the development of vaccines designed to prevent Th2-mediated disease and indicate that prior lung BCG vaccination can alter the pattern of subsequent host inflammation.

Trichosporon asahii-induced asthma in a family with Japanese summer-type hypersensitivity pneumonitis

BACKGROUND

Trichosporon species frequently induce summer-type hypersensitivity pneumonitis (SHP), which is the most prevalent type of hypersensitivity pneumonitis (HP) in Japan, but have not been reported to induce asthma.

OBJECTIVE

Evaluation of a case of asthma induced by Trichosporon asahii.

METHODS AND RESULTS

This report describes a 46-year-old Japanese man who developed asthma induced by T. asahii, following symptoms of HP attributable to the same pathogen, in a case of familial occurrence of SHP. This patient lacked typical findings of HP in his radiograph but had an elevated level of eosinophils in his bronchoalveolar lavage fluid. Open lung biopsy, however, revealed typical pathologic findings of HP when he was free of asthmatic symptoms. His serum was also positive for anti-T asahii antibody, as are the sera of SHP patients. Nevertheless, provocation tests, including returning home and inhalations of T. asahii antigen, reproduced asthmatic features such as airway hyperresponsiveness and reversible bronchoobstruction, but not the features of HP. A skin test with the same antigen also evoked an immediate allergic reaction. An IgE mechanism was suspected but could not be proven by radioallergosorbent test. The patient's son and daughter displayed typical features of SHP, associated with compatible results in their radiographs, bronchoalveolar lavage fluid analysis, serologic and pathologic examinations, and provocation and skin tests.

CONCLUSIONS

To our knowledge, this is the first case of extrinsic asthma, and of coexistent asthma and HP, induced by T. asahii. The patient initially displayed symptoms typical of SHP, which were subsequently replaced by more typical asthmatic symptoms.

IL-5 Is Required for Eosinophil Recruitment, Crystal Deposition, and Mononuclear Cell Recruitment During a Pulmonary Cryptococcus neoformans Infection in Genetically Susceptible Mice (C57BL/6)

CBA/J (highly resistant), BALB/c (moderately resistant), and C57BL/6 (susceptible) mice displayed three resistance patterns following intratracheal inoculation of Cryptococcus neoformans 52. The inability to clear the infection correlated with the duration of the eosinophil infiltrate in the lungs. The role of IL-5 in promoting the pulmonary eosinophilia and subsequent inflammatory damage in susceptible C57BL/6 mice was investigated. C57BL/6 mice developed a chronic alveolar, peribronchiolar, and perivascular eosinophilia following C. neoformans infection. This resulted in the accumulation of intracellular Charcot-Leyden-like crystals in alveolar macrophages by wk 4 and the extracellular deposition of these crystals in the bronchioles with associated destruction of airway epithelium by wk 6. IL-5 mRNA was expressed in the lungs, and injections of anti-IL-5 mAb prevented eosinophil recruitment and crystal deposition but did not alter cryptococcal clearance. Depletion of CD4+ T cells (but not CD8+) ablated IL-5 production by lung leukocytes in vitro and eosinophil recruitment in vivo. Neutralization of IL-5 also inhibited the recruitment of macrophages, CD8+ T lymphocytes, and B lymphocytes by 47 to 57%. Anti-IL-5 mAb inhibited CD4+ T lymphocyte recruitment by 30% but did not affect neutrophil recruitment. Thus, the development of a chronic eosinophil infiltrate in the lungs of C. neoformans-infected C57BL/6 mice is a nonprotective immune response that causes significant lung pathology. Furthermore, IL-5 promotes the recruitment and activation of eosinophils, resulting in the recruitment of additional macrophages and lymphocytes into the lungs.